Wireless receiving apparatus



' Feb. 28, 1928.

A. MAVROGENIS WIRELESS RECEIVING APPARATUS Filed Jan. 1926 2 ShQtS-Shfl1 0 04/. I J/a/m 617/3" Feb. 2s, 1.928.

1,660,803 A. MAVROGENIS WIRELESS RECEIVING APPARATUS Filed Jan. 2. 19.262 Sheets-Sheet 2 Lmmmd Mwg I ceiving apparatus.

Patented F b. 2c, 1923.

UNITED STATES msrora mvnoemsorirrnwaum, wrsconsm.

WIRELESS nncnr'vrne APPABAWS.

Application ma January 2, 192a. Serial at; 78.877.

This invention relates to a wireless 1'e'- In wireless receiving systemstwo main schemes have been used .for operating the vacuum'tubes. Eithera set of atteries for the filament and for the plate have been used orelse B-battery eliminators have been substituted for the plate battery.In the first case there is a decided variation in the action of thebattery from day to day, and consequently adjustments have been made toeliminate these variations. The batteries have to be recharged orremoved at frequent intervals. In the second place, the eliminators areexpensive apparatus and require bulky choke coils and condensers and,even under the best conditions, do not entirely eliminate the-hum of thealternating current. This invention is designed to overcome the defectsnoted above, and objects of such invention are to provide a wirelessreceivin apparatus all parts of which are energlz from commercialalternating current mains,

- and in which no objectionable hum occurs.

In general this invention is an improvement over that described in myPatent Number 1,570,444, of January 19, 1926,. for wireless apparatusand also it is to'be noted that the tubes employed in the systemdisclosed in this application are the subject matter of my Patent Number1,638,499, of August 9, 1927, for electron discharge devices.

Further objects are to provide a stem in which a unitary electrondischar e evice is used in the circuits in which the ter con denser,leak resistance, otentiometers, choke coils and similar devices aredispensed with,. for the unitary device itself replaces all ofthe'separts.

Further objects are to provide an apparatus for wireless reception inwhich, although the parts are energized from commercial alternatingcurrent mains, fluctuations of voltage or current are wholly avoided,-and .a smooth and dependable operation is assured.

Further objects are to provide a novel form of wireless'receivingapparatus which may be employed in a small space in which the parts usedare ,of light weight, and which may be'relatively cheaply produced incomparison. to the expensive systems heretofore known.

Further objects areto provide a wireless receiving apparatus in whichthevacuum Reissue tubes or unitary electron dischargedevices tector oras an amplifier r radio ener whether of audioor radio frequency, andiiii provide a system in which the plate voltage may be regulated.

Further objects are to provide a wireless receiving apparatus in whichthe device may be kept 1n a regulated condition for an indefiniteperiod, and may be relied upon to operate identically under the samecondit1ons from day to day, and in which there is no falhng ofi ofvoltage due to continued or prolonged use.

Embodiments of the invention are shown in the accompanying drawings, inwhich':-

' Flgure 1 shows one form of the invention employing a 4-prong vacuumtube.

' Figure 2 1s a corresponding view showing a modlfied form of apparatus,using a stepup transtormer and a 5-prong vacuum tube. Figure 3 1s a viewof a further form of the invention.

Referring to Figure 1, it will be seen that each of the unitary electrondischarge devices lndlcated by the reference characters A, B and C, areof the same construction and consequently a description of one willsuffice.

Consider for instance one of the devices. It Wlll be seen that suchdevice includes a lnghly evacuated vessel within which an audionapparatus, indicated generally by the" reference character 2, arectifier apparatus indicatedat 3, and a current limiting apparatus,mdlcated generally at 4, are employed.

The audion apparatus comprises a plate or anode 5,-a grid 6 and anequipotential cathode 7 This cathode is heated by means ofa filament 8.a i A The rectifier comprises an anode 9and a cathode 10, such cathodebeing heated by a filament 1 Y are interchangeable and mag be used as ade- The current limiting device comprises'an I cathode being indicatedby the conductors 15 and 16.

It is to be noted that a resistance 17 is connected between the cathode13 of the current limiting device and the outgoing lead 15. Also acondenser 18 is connected be- Y the conductor 23 which in turn isconnected identical in constructiombut their leads areindicated,respectively,at 16,19;20 and 21-22," as they are connected tod fferent portions of the system as will hereinafter appear.

In the form of the invention shown In Figure 1, the conductor 15 isconnected to through an adjustable resistance 24' to one of the powermains, as indicated at 25. The lead 16 is connected to the conductor 26and from thence to the other power main 27-. Thus, by adjusting thevalue of the resistance 24, the heating of the filaments 8, 14

and-11 may be simultaneously controlled.

It is to be noted also that the anode 9 of therectifier is connected tothe-lead 16 and that the cathode 10 of such rectifier is connected tothe anode 12 of the current limiting device and also to one side of thecondenser 18. 4

The cathode 13 .of the current limiting device is connected to the plateor anode 5 of the audion and also to one side of theresistance 17.

The operation of the rectifier andburrent limiting device is detailed inmy Patent Number 1,570,444,noted above. However, it may be stated thatthe cathode 10 is heated by the filament 11 and consequentlyunidirectional current flows between the anode 9 and the cathode of therectifier 3. This unidirectional current is pulsating but the pulsationsare, somewhat smoothed out by the condenser 18.. This current passesto'the current limiting device 4. In this device,

:current limiting device is of constant value and passes throughthe'resistance 17 back to the lead 15 and from thence back to thecondenser 18. In addition to this, the current also passesto the plate 5of the audion 2.. Obviously, since the resistance 17 is of 'fixed' valueand the current limiting device worked above saturation point, theaudion is supplied with a potential of consistent value.

Upon reference to Figure 1, it will be seen that th'e'first unitarydevice Ahas its grid connected by, means of the conductor 28 with oneend of the secondary 29 of the in ductively' coupled coils at the lefthand side of Figure 1. The lower end of the coil 29 is connected througha ground condenser and resistance to the bus bar'or sub-main 23.

The antenna 30 "is connected through the primary 33 being connected tothe'conduc-,

tor 23.

The secondary 34 of the radio frequency transformer has one'endconnected to the bus bar or conductor 35 and its other end connectedthrough a grid condenser and leak resistance to a grid 6 of the'secondunitary device, or second vacuum tube indicatedby the referencecharacter B.

It is to be noted that a variable. condenser 36 is connected across theterminals of the secondary 34 and similarly a variable condenser 37 isconnected between the terminals ofthe secondary 29. This system,therefore,

shows a tuned radio frequency system in which one stage of tuned radiofrequency am lification is employed, although, obvious y, any number ofstages may be similarly employed. e

The vacuum tube B is similar in all respects to the vacuum tube A and,therefore, a detaile'ddescription is not necessary. The cathode 7 ofsuch vacuum tube B is connected through the primary 38 of an audiofrequency transformer to the bus bar 35. If desired, a resistance 39 maybe employed. The resistance 39 is ut in the detector circuit to reducethe v0 tage impressed on this circuit. his use of the resistance permitsthe using of'identical tubes throughout the entire apparatus, and doesnot require, therefore, a specially formed detector. Further, the usualby-pass condenser 40 is bridged across the terminals of this primary.

The secondary 41 of the audio frequency transformer has one endconnected to the bus bar 35 and its other end connected to the grid 6 ofthe vacuum tube C. The cathode 7 of such vacuum tube is connected bymeans of the conductor 42 with any translating device 43 such as thetelephone receiver being bridged by means of the by-pass condenser 44 inthe usual manner.

It is to be notedthat the leads 20 and 22 from the filaments of thevacuum tubes B and C are connected to thebus bar 26 While the leads 19and 21 of such'filaments are connected to the bus bar 35. This bus bar35 is joined to the main 25 by means of a variable resistance 45.

In operating the device, it is clear that the exact adjustmentdesiredfor the filaments may be attained by adjusting the variable resistance24 and 45. The adjustment of the '45. controls the plate volgge ofv thetubes B and C and also the current flowing through their filaments.

It will be seen from referenceto Figure 1 that the conductors leadingout of the vacuum tubes may be formed as prongs and consequently onlyfour prongs are necessary for this type of apparatus.

The exact details of the vacuum tubes are illustrated and claimed in myPatent Number 1,638,499, noted above.

Further, from reference to Figure 1, it is apparent that an extremelysimple wiring scheme may be followed with this system as the devices A,B and C are self-contained and unitary and do away with batteries orbattery elimirgtors and also with choke coils, potentiome ers and otherapparatus of this type. Consequently, the minimumof wlring is requiredin a set or system of this yp Further, it is apparent that the apparatuswill give identically the same result under the same conditions ofadjustment and that no falling 0a in voltage and no hum from thealternating current supply mains will be produced.

In the form of the invention shown in Figure 2, a somewhat similarscheme has been shown with the exception that 5- pronged vacuum tubesare employed. Three of these tubes are illustrated, as indicated at 46,47 and 48. These tubes are identical with those previously describedexcept for the fact that the anode 49 of the rectifier is provided witha separate prong or conductor 50 which extends through the walls of thevessel. These conductors 5O 'join the bus bar 51 which in turn is,connected to one end of the secondary 52 of the step-up transformer. Theother end of this secondary is connected to one end of the primary 53 ofthe transformer and through a conductor 54 is .connected to one of themains 55. The other end of the primary 53 of the step-up transformer isconnected to the other main- 56. However, it will be noted that thevariable resistance 45 is still interposed in the circuit supplying theanodes 49 of the rectifiers as well as the filaments for 'the tubes 47and 48 and the voltage impressed upon the anode 49 of theseequipotential cathode 60 of the device, instead'of the connectionillustrated in Figure 1..

It is to be understood that the invention may be applied to othersystems than the one shown and also may be modified as to the number ofthe unitary electron discharge 'tions occurring in such mains fromeffecting any portion of the apparatus.

It is to be noted also that the tubes are interchangeable in the system]and consequently a single type of tube is needed for such system.

Attention is directed to either of Figures 1 or 2. Consider, forexample, Figure 1. Current flows from the cathode of any one of thedevices through the output or intervalve coupling device to the busbar35. There is a drop in voltage'through this output instrumentality.Further, the grid is connected through its input coil to the busbar 35.Consequently, the grid is maintained at a negative potential withreference to the cathode of the audion.

Although the invention has been described in considerable detail, suchdescription is intended as illustrative rather than limiting astheinvention may bevm'iously embodied and as the scope of such inventionis to be determined as claimed.

I claim:

1. In a radio receiving apparatus, the combination ofa source of radiosignal energy,

a plurality of unitary discharge devices each including an audion havingan equipotential cathode, an anode, a grid, arectifier including acathode and an anode, a thermionic current limiting device connectedbetween said rectifier and audion and having a cathode and an anode, afilament for heating each of said cathodes; a reproducing device; inputand output circuits connecting said devices with said source of signalenergy and wlth said reproducing device; a source of low frequencyalternating current, circuits connecting said filaments, the anodes ofsaid rectifiers, and the cathodes of said audions with said alternatingcurrent source, and.

means for simultaneously increasing ordecreasing both the temperature ofsaid filaments and the total voltage supplied the output'circuits ofsaid audions.

2. In a radio'receiving apparatus, the combination of a source of radiosignal energy, a plurality of unitary electron discharge devices eachincluding an .audion having an equipotential cathode, an anode, a grid,a.

rectifier including a cathode and an anode, a thermionic currentlimiting device connected between said rectifier and audion and having acathode and an anode, a filament for heating each of said cathodes; areproducing device; input and output circuits connecting said'deviceswith said source of slgnal energy and with said reproducing device, saidcircuits including a connection directly from the equipotential cathodeof the audion of one device through the output circuit of such device tothe input circuit of a succeeding device; a source of low'frequencyalternating current, circuits connecting said filaments, the anodes ofsaid rectifiers, and the cathodes of said audions with said alternatingcurrent source; and means for simultaneor decreasing both the temouslyincreasin filaments and the total voltperature of said age supplied theoutput circuits of said andlons.

3. Ina wireless receiving a paratus, the

combination. of a source of ra io signal energy, a reproducing device, aplura1ity of unitary electron discharge devices; each of said unitary'devices including a rectifier having an anode, a cathode, an audionhaving an anode, an equipotential cathode, an interposed grid and aheater for the oathode, andmeans for smoothing out the current suppliedby said rectifiers, a source of low frequency alternating current forenergizing said unitary devices, input and out-v put circuits ,jorsupplying signal energy from one device to a succeeding device, meansfor simultaneously lncreasing or decreasing both the temperature of theheaters and the total voltage supplied the output cir cuits of a grou osaidaudions, said means including an adjustable resistance.

4. In a wireless receiving apparatus, the combination of a source ofradio signal energy, a reproducing device,- a plurality of unitaryelectron discharge devices; each of said unitary devices including arectifier having an anode, and a cathode, an audion having an anode',-anequipotential cathode, an interposed grid, and a heater for saidequipotential' cathode, and means for smoothing out the current suppliedby said rectifiers, low frequency alternating current supply mains, andinter-valve couplings for supplying signal energy from one device toasucceeding device, the input circuit, the output circuit and oneterminal of the audion heater of each of a group of unitary devicesbeing connected directly to a common terminal and to one of saidmains,'the other of said mains being connected to the other terminal ofsaid heaters and to said rectifiers.

5. In a wireless receiving apparatus, the

combination of a source of radio signal energy, a reproducing device, aplurality ofing an anode, anda cathode, an audion having an anode, anequipotential cathode, a n interposed grid, and a heater for saidequipotential cathode, and means for smoothing vice, the input circuit,the output circuit and one terminal of the audion heater of a group ofunitary devices being connected directly to a common terminal, and atransformer having a primary energized from said source of alternatingcurrent and having a secondary, one end of which is connected to saidcommon terminal and the other end of which is connected to therectifiers of the said group of unitary devices.

6. In a radio receiving apparatus, the.

combination of a source of radio signal energy, a group of unitaryelectron discharge devices, each including an audion having anequipotential cathode, an anode, a grid, and a rectifier including acathode and an anode for supplying current to said audion, smoothingmeans connected with said rectifiers for smoothing the current suppliedto said audions, filaments for heating the oathodes of said audions, areproducing device, input and output circuits connecting said deviceswith said source of signal energy and with said reproducing device, asource of low frequency alternating current, and circuits connectingsaid filaments, the anodes of said rectifiers and the cathodes of saidaudions with said alternating current source, means for simultaneouslyincreasing or decreasing both the filament temperature and the totalvoltage supplied the output circuit of at least one of said audions,said means comprising an adjust-able resistance common to said lastmentioned circuits. I

7. In a wireless receiving apparatus, the

combination of a source of radio signal energy, a reproducing device, aplurality of unitary electron discharge devices each including an audionhaving a cathode provided with a heating circuit, an anode, a grid, arectifier having an anode and a cathode for supplying current to saidaudion anode, smoothing means connected with said rectifiers forsmoothing the current supplied by said rectifiers, inter-valve couplingmeans for supplying signal energy from one device to a succeedingdevice, a single source of low frequency alternating current forsupplying the heating circuits of a group of such au dions, and meansincluding the inter-valve coupling means for maintaining aconstantnegative potential on the grid of at least one of said unitary devices.a

8. In a Wireless receiving'apparatus, the combination of a source ofradio-signal energy, a reproducing device", a group of unitary electrondischarge devices each includa rectifier having ananode and a cathodeing an audion havinga cathode provided with a heating circuit, a gridand an anode,

for supplying current to said audion anode, smoothing means connected tosaid rectifiers for smoothing the current supplied to said audionanodes, inter-valve coupling meansfor supplying signal energy from onedevice to a succeeding device, a source of 9. In awireless'receivingapparatus, thecombination of'a source of radio signalenergy, a reproducing device,'agroup of unitary electron dischargedevices, each including an audion havinga heated cathode provided with aheating circuit, an anode and a grid, and a current limiting devicehaving an anode and a cathode for cotrolling the energy supplied theaudion anode, a source of low frequency alternating current, rectifyingmeans connected with said source of alternating current for supplyingsaid audions through said current limiting devices, all of the heatingcircuits of said audions being directly electrically connected togetherand supplied from said source of alternating current, inputand outputcircuits connecting said devices and the reproducing device, saidcurrent limiting devices being connected in series with the outputcircuits of said audions, and the input circuits of said audions beingconnected to a common terminal.

10. In a wireless receiving apparatus, the combination of a source ofradio signal .energy, a reproducing device, a group of unitary electrondischarge devices each including an audion having a cathode providedwith a heating circuit, a grid and an anode,

a rectifier having an anode and a cathode for supplying current to saidaudion anode, I

smoothing means connected to said rectifiers for smoothing the currentsupplied to said audion anodes, inter-valve coupling means for supplyings gnal energy from one device to a succeeding device, a source of lowfrequency alternating current for supplying said devices, said smoothingmeans and rectifiers being connected to said alternating current source,the cathode of at least one of the audions being connected through thecorresponding output circuit to the smoothing means, whereby currentflows from said cathode of the last mentioned audion through the outputcircuit to the smoothing means.

. In testimony that I claim the foregoing I have hereunto set my hand atMilwaukee. in the county of -Milwaukee and State of Wisconsin.

ARISTOTE MAVROGENIS.

